I clean the box, hoping that next spring our bluebirds will come back to raise yet another brood. Around March, the pair returns to our snow-covered yard in the high mountains of Colorado. All summer, the brilliant-blue male and subtle-colored female perch on our swing set,

rooftop or the railing of our deck. To us, their soft calls and chirps have come to mean summer.

My two young children watch the birds snatch grubs from the flower bed, dive-bomb after flying insects or sway in the wind on sagebrush twigs. The birds take turns sitting on the eggs and, before long, it’s time for the chicks to flop out of the box to spend a few days beneath our deck until they’re ready to fly.

Living at 8,000 feet, our winters are long and harsh. We spend our summers outdoors as much as possible. Bedtime slips into the late evening as the children make loopy circles on the driveway in their tricycles beneath a purple twilight sky. Too soon, October comes, and I’m sorry when the bluebirds decide it’s time to go, because that means summer is truly gone.

I built this bluebird box with my grandfather long before I moved to Colorado, and had a family of my own. I don’t know how the idea got started. I had recently quit my job and my then-boyfriend, and moved back home to the Midwest from a foreign country to start again. So during the week, instead of looking for another job, my grandfather and I worked in his garage with his well-used tools.

He was a retired dentist, teacher and lifelong carpenter who loved birds and trees, and believed in doing things right. So he patiently taught me Carpentry 101, while my grandmother kept a pot of coffee warm for our frequent breaks at the dining-room table. There I was surrounded by the noises of my childhood—the lazy hum of the refrigerator kicking on, the loud creek of the deep-freeze door being opened and the tick-tock of the grandfather clock—built by my own great-grandfather—which could never keep the right time.

During our breaks, we talked about the years my grandparents spent in Puerto Rico, or the bullheads great-uncle Jake used to pull out of the Blue River, which wasn’t so blue anymore. Most of these stories were ones they had been telling me all my life. But I didn’t mind.

When my grandfather died two years later, my grandmother gave me one of the bluebird boxes we had made. By that time, I had married and moved to Colorado. As luck would have it, we live in a wide-open subdivision—the perfect habitat for bluebirds.

Every fall, when I tightly close the lid of the bluebird box for winter, I think about how the things you build can have a purpose greater than you imagine. And how the people you have lost come back to you again and again in ways you couldn’t have known.

Bergen lives in Granby, Colo.